Process of making a contact mass.



JOHN WOODS IBECKMAN, OF NIAGARA FALLS, CANADA, ASSIGNOR T0 AMERICAN CYANEMID COMPANY, OF NEW YORK, N. Y., A CORPORATION OF MAINE.

PROCESS OF MAKING A CONTACT MASS.

No Drawing.

Specification of Letters Patent.

Patented Oct. 31 1911.

Application filed December 14, 1909. Serial No. 533,094.

tion, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a contact mass and process of making the same and has for its object to produce a material which will facilitate the extraction of nitrogen from the air.

With this and other objects in view the invention consists in the novel composition of matter and process for producin the same; more fully hereinafter disclose and particularly pointed out in the claim.

In carrying out this invention, I preferably take a mixture of finely divided copper oxid, silica, and of granular alumina and so proportion them that a very small quantity of silica will, upon heating, chemically combine with its equivalent of copper oxid to form a bonding material which,

temperature should not be above the boiling point of the said oxid. In practice I have found that it is advantageous to not heat the material above 1200 C., for otherwise the copper oxid becomes too fluid, and is liable to run olf the upper strata of the mass. The lower limit of temperature is that degree at which the copper oxid will become sufficiently fluid to coat the granules, and this ma be determined by inspection.

practice the mixed oxids with a very small quantity of silica are heated to a temperature above the melting point of copper or above 1200 C. in any suitable furnace, when the silicate bonding material is formed, while the copper oxid in excess is melted and diffuses together with the re duced copper throughout the whole mass and coats the individual grains. Therefore theima'ss which is found upon cooling to be open and porous is solidly bound together and has each of its grains covered with a coating of copper oxid or copper. The thickness of the copper film Wlll depend upon the percentage lected and it may, therefore, suit'specific requirements. As an illustration of the process the following specific example is cited:-Take 40 pounds of fused granular aluminum oxid, or alundum 9 ounds of finely divided copper oxid; and (seven tenths) of 'a pound of powdered silica. The aluminum oxid may be of any sized grain, but I prefer one that will pass through al or a 16 mesh sieve. The copper oxid, as well as the silica, are preferably ground so fine that they will passthrough a one hundred mesh sieve, although this is not'essential; The constituents may be thoroughly mixed conveniently in a graphite crucible and heated for five hours at a temperature higher than the melting point of copper, when after being taken out they will be found to be firmly bound together in an open porous mass ofiering no appreciable resistance to the passage of air therethrough and each grain will be coated with a film of copper oxid, or of copper matte, or of metallic copper. If this porous mass is next heated to the requisite temperature in a suitable closed vessel, and any suitable reducing gas such as hydrogen, methane, carbon monoxid or producer gas, or any mixture of these, be passed through the same, substantially all the copper oxid will be reduced. to copper, and each grain will be found to be coated with a film of metallic copper. The degree of heat necessary for this reduction is readily ascertained by gradually raising the temperature of the mass until metallic copper is observed. If air is next passed through the heated porous mass at a slightly lower temperature and which now has a very large copper coated surface, the copper will take up the oxygen from the air to reform the copper oxid, and nitrogen substantially free from oxygen will pass throu h and may be recovered. The copper oxi films formed by the passage of air through the porous mass may next be reduced to metallic copper in the manner be varied to of copper originally seindefinitely.

It is obvious that instead of pure ah imina,

Lin 4 other materialscontaining alumina, such as .corundum, emery, and garnetnm-a w thout materially reducing the e be used, ciency of theprocess. It is also evident that the oXids of othenmetals than copper may be reducedby'this process and that if the recovery of nitrogen free from oxygen is desired,-iron oxids may be freely substituted for copper oxids. And in such-cases the mass is heated to that temperature at whichit is observed the iron oxid will flow freely over the individual grains. This'temperature is probably a3b0ufi1300 G. to 1400'C.,if the double o'xid Fe O is employed. It is likewise evi- 'making sulfuric acid,- and in other catalytic p or chemical processes. Therefore, since it is evident that those skilledthe art may widely vary my product and process for producing the same without departing from the spirit of-my invention, I do not Wish to be limited to the above disclosure except as may be required by-the claim.

What I'claim is The process of making a porous contact mass having the surfaces of its pores coated with films containing copper, which consists inmixingsuitable proportions of finely powdered silica. and copper oxidwith .granular alumina, and in heating the mixtureto a temperature above the melting point of copper to permit the silica to reactwith a portion ofthe copper oxidand to cause the excess of the latter to coat the individual particles of the-aluminum oxid, substantially as described.

In testimony whereof, I aflix my signa 'ture, in presence oftwo witnesses.

JOHN WOODSBEClQl IAN.

- Witnesses:

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